Transgenic animals give investigators a powerful system for either targeting the expression of a gene to a specific tissue(s) or obliterating the expression of a specific gene. Therefore, transgenic animals are an excellent tool for directly evaluating the role of a specific gene (or genes) in an age-related disease or in aging. The Transgenic Core will provide all services and services and resources required to produce transgenic mice, transgenic rats, and transgenic mice with gene knockouts for Center investigators. Because the techniques for producing transgenic rats or mice with gene knockouts are not currently available at UTHSC-SA, an important goal of this Core is to develop these techniques. The specific aims of the Core are as follow: 1. To produce transgenic mice by microinjection and to identify the transgenic mice by PCR and DNA hybridization techniques. The number and integration sites of the transgene also will be determined by examining DNA from the transgenic mice. 2. To develop the techniques for producing transgenic rats by microinjection and to use these techniques to produce transgenic rats for Center investigators. Transgenic rats will be identified by PCR and DNA hybridization techniques, and the number and integration sites of the transgene will be determined. 3. To develop the techniques for producing transgenic mice with gene knockouts using homologous recombination and to use these techniques to produce transgenic knockout mice for Center investigators.